Refactor docker-compose.yml by removing unnecessary lines and cleaning up formatting

docker-compose.yml

@@ -1,10 +1,8 @@
-version: "3.9"
-
 services:
   backend:
     build:
       context: .
-      dockerfile: Dockerfile  # Use Dockerfile.prod for production
+      dockerfile: Dockerfile # Use Dockerfile.prod for production
     ports:
       - "8000:8000"
     env_file:
@@ -12,8 +10,5 @@ services:
     environment:
       DATABASE_URL: "{DATABASE_URL}"
     volumes:
-      - .:/app  # sync code for hot reload
-    depends_on:
-      - db
-
+      - .:/app # sync code for hot reload